US2306625A

US2306625A - Hydraulic centrifuge

Info

Publication number: US2306625A
Authority: US
Publication date: 1942-12-29
Anticipated expiration: 1959-12-29

Description

Dec.29,1942. 1 HAZ-EN 2,306,625-

HYDRAULIC CENTRIFUGE Filed Dec. 50, 1940 CLOSED O- OPEN INVENTO EDWARD J- HAZEN-= '3 Patented Dee. 29, 1942 UNITED STATES PATENT OFFICE HYDRAULIC GENTBIFUGE Edward John Hazen, Clifiside Park, N. J., as-

signor to S. S. Hepworth Company, a. corporation of New York Application December 30, 1940, Serial No. 372,232

6 Claims.

the sugar processing art ordinarily comprise an impulse wheel with one or more associated jets or nozzles and a vertical drive shaft that carries a perforated basket at its lower extremity. The material to be centrifuged is loaded into the basket which is then rotated at high velocity to expel unwanted fluid matter, leaving the sugar crystals within the, basket. The economics of the process are such that the centrifuge is in substantially continuous operation, one cycle of loading the basket, acceleration to high velocity, deceleration and unloading following immediately after another. Each cycle may require only a few minutes and each load may weigh a substantial fraction of a ton.

The present invention is concerned more particularly with a hydraulic centrifuge of the kind described in which one jet or nozzle or a set of them is used primarily for supplying the power required to accelerate the machine quickly to high velocity and another jet or nozzle or set of them is used for supplying the relatively small power required for constant velocity, high speed rotation. The one may be'of a large size requiring a relatively large amount of water and the other may be of correspondingly small size.

The principle object of the present invention is to reduce the water power consumption of a hydraulic centrifuge and to facilitate control of the jets in furtherance of this object. Another object is to effect automatic sequential operation of jets utilized for acceleration and for constant velocity rotation respectively. A further and more particular object is to facilitate operation of the valves associated with the several jets and to insure their operation at prescribed points in the centrifuging cycle.

In accordance with the invention as embodied in preferred form a high power jet especially adapted for acceleration of the machine is automatically interrupted at a predetermined point in the centrifuging cycle and a low power jet is used alone for constant high speed rotation. In this preferred form both jets are put into operation on manual opening of the starting valve and a device, preferably a timing device that is started simultaneously with the opening of the starting valve, operates when a predetermined point is reached in the cycle to close a valve individual to the high power jet. The torque required to operate the last mentioned valve is derived from the main operating header, or other point in the hydraulic system of substantially equal pressure, thereby insuring quick and timely closing of the valve despite the high hydraulic pressure to be controlled. I

The nature of the present invention and its various features, objects and advantages will appear more fully from the following description of the preferred embodiment that applicant has chosen for purposesof exposition and illustration in the accompanying drawing. 7

Referring now to the drawing there is shown a hydraulic centrifuge comprising a chamber l in which is housed an impulse wheel 2 arranged in operative relation with a pair of nozzles 3 and 4 for driving the centrifugal basket (not shown) that is mounted on the lower end of'the vertical driving shaft or spindle 5. Hydraulic power for supplying the nozzles is derived from the main header 6, which may carry water at a pressure of 250 lbs. per square inch or higher, for example, through a branch pipe 1 and main valve 8. Following valve 8 the branch pipe divides into two separate pipes 9 and I0 which lead to the nozzles 3 and 4 respectively. Nozzles 3 may be of such size that the jet power it delivers is sufficient to maintain the speed of the centrifuge once the latter is accelerated to full operating speed. The latter in modern machines may be of the order of 1800 R. P. M. or somewhat higher. Nozzle A may be of fairly large size adapted to deliver a jet of such power as to accelerate the centrifuge quickly to high speed.

In the supply pipe in to nozzle 4 there is interposed a valve H which is arranged in a manner to be described so that it is automatically and quickly closed at a predetermined point in the centrifuging cycle. Provision is made also for the automatic opening of valve II at a suitable time prior to the beginning of another cycle of centrifuging operation. Valve 8 is arranged for manual opening and closing and for this purpose is connected through a connecting rod 12 to a bell crank lever l3 that isintegrally connected to operating handle l4, With the latter in the position illustrated valve 8 is open, and on depressing handle I4 the system of levers functions to close the valve.

From the nozzle side of valve 8 a small branch pipe l5 extends to an inlet in the upper por tion of an air compressing chamber 20. Interposed in branch pipe 15 is a needle valve IE or an equivalent device that may be manually adjusted to regulate the flow of water into chamber 20. From the bottom of chamber a pipe 2| is brought out and extended through a selfclosing valve 24 which leads to a drain as indicated. Opening of valve 24 is effected by means of a cam 26 which is mounted on a shaft 21 that turns with operating handle M, and which displaces the valve member when handle I5 is depressed to close valve 8. Branching from pipe 2| is a control pipe 23 that leads to a connection near the bottom of a hydraulic cylinder 30. From a point near the top of hydraulic cylinder 30 a control pipe 3! leads to header 6, or preferably to branch pipe 7 as shown. Within cylinder 30 is a piston 32 which is attached through a vertical connecting rod 33 to the operating lever associated with valve l I.

Further details of construction will appear in the following description of the mode of operation of the apparatus depicted. Supposing that one centrifuging cycle has just been completed the conditions existing are as follows: Valve 8 is closed, valve I l is open and piston 32 is at a correspondingly low position in cylinder 3%, valve 24 is open and chamber 29 is filled with air. On raising handle [4 to start another cycle valve 8 is thereby opened and water rushes from the header 6 into nozzles 3 and 4. The powerful jet delivered from nozzl 4 thereupon eifects rapid acceleration of the machine, while the jet from nozzle 3 contributes to the acceleration in proportion to its size.

Immediately upon opening main valve 8 water passes through pipe l5 into chamber 20, at a rate controlled by the setting of needle valve iii. The water entering chamber 26 promptly closes valve 24, or valve 24 may be automatically springclosed, and as the water accumulates, it begins to compress the air in the upper portion of the chamber 20. The air pressure continues to increase toward a limiting value fixed by the water pressure at the nozzle side of valve 8 which is approximately the same as the pressure in header 6. The resulting water pressure in chamber 20 a is communicated through pipe 23 to the underface of piston 32. On the upper face of piston 32 the Water pressure communicated by pipe 3| is that of header 6, but inasmuch as the area of the upper face is somewhat less than that of the the pressure on the lower face of piston 32 becomes sufilcient to displace the piston and close valve H. The predetermined time fixed by ad- Accordingly, after a predetermined time fixed by the adjustment of needle valve l6,

justment of valve 46 may in a typical case be about four minutes, and in any case it is so selected that valve H closes when the centrifuge has been accelerated to top speed or at least to a speed high enough that the jet from nozzle 3 is sufiicient to alone carry the load. Pressure gauge 40 at the top of chamber 2Q facilitates adjustment of the needle valve. 7

After any desired period of full speed operation appropriate for the particular material being centrifuged, valve 8 is closed by manual operation of handle I l. The high speed jet from nozzle 3 is thereby interrupted and the centrifuge may be decelerated by braking means (not shown) for unloading and reloading. Simultaneously with the operation of handle it cam 26 forces valve 24 open, thereby allowing the water accumulated in chamber 20 to be rapidly expelled with the aid of the air pressure above it. The water may be completely expelled and the pressure reduced to atmospheric pressure in twenty seconds in a typical case. As chamber 26 is being emptied the pressure communicated to the lower face of piston 32 is thereby reduced and a point is reached where the header pressure on the upper face of the piston becomes sufficient to force reopening of valve H. Th apparatus is then conditioned for the start of the next cycle.

From the foregoing description it will be understood that economy of hydraulic power is secured in providing for stoppage of the high power jet at a predetermined point in the centrifuging cycle such that further operation may be efficiently carried on by the low power jet alone, and paricularly in the provision for automatic interruption of the high power jet by means beyond the immediate control of an operator and therefor not subject to either untimely operation or omission on the part of the operator. It will be further appreciated that whereas the difficulty involved in manual operation of large valves in a high pressure hydraulic system precludes accurate timing of the operation of such valves, the system illustrated and described utilizes the high pressure of the main hydraulic supply in a novel and advantageous manner to facilitate the timed operation of such valves. This is especially important in the case of centrifuga1 machines employed in the processing of sugar-bearing materials, for these are started and stopped every few minutes and each operator has a large number of the machines to control. The labor involved in manual operation of the control valves is accordingly quite substantial, and a correspondingly substantial advantage and conservation of manual effort on the part of the operators is obtained by application of the present invention and utilization of th pressure of the main hydraulic source for supplying the operating power required.

Although a single embodiment of the invention has been employed in the foregoing exposition it will be apparent to those skilled in the art that in several respects the embodiment is illustrative only and that the invention is susceptible of application in practice in a variety of other forms within the spirit and scope of the appended claims.

What is claimed is:

1. In a machine comprising an impulse wheel, means for supplying water under high pressure to said machine, and a plurality of nozzles arranged to impel the supplied water into driving relation with said wheel, a valve controlling the admission of water to all of said nozzles, a valve operable to block the admission of water to one of said nozzles, means for operating said lastmentioned valve comprising a hydraulic piston and means for applying water at said high pressure to said piston to close said last-mentioned valve, and timing means initiated on the opening of said first-mentioned valve for controlling the application of the water to said piston.

2. In a hydraulic turbine arrangement comprising a plurality of nozzles, and a source of water under high pressure, a manually operable valve controlling the admission of water from said source to said turbine, means for supplying said nozzles with the water admitted to provide jets for driving said turbine, a valve for controlling the water supply to one of said nozzles, hydraulically operable means for opening and closing said last-mentioned valve, and actuating means for supplying water from said source to said hydraulically operable means to actuate said last-mentioned valve in the closing direction, said actuating means being controlled by the opening of said manually operable valve and containing means to adjust the rate of supply of water to said hydraulically operable means.

3. In a hydraulic turbine arrangement including a source of Water under pressure for driving said-turbine, an air compressor chamber, means for introducing water from said source into said chamber at a predetermined rate whereby air in said chamber is compressed progressively toward the pressure of said source, a differential hydraulic relay comprising a cylinder and piston, and hydraulic means for subjecting said piston to the opposing pressures of said source and said chamber, respectively, whereby said relay is operated an interval of time after water has been first introduced into said chamber.

4. A combination in accordance with claim 3 comprising a main valve interposed between said source and said turbine, and means responsive to opening of said valve for initiating the flow of water from said source into said chamber,

5. A combination in accordance with claim 3 comprising a main valve interposed between said source and said turbine, and means responsive to closing of said valve for discharging thewater accumulated in said chamber.

6. In a turbine arrangement comprising a plurality of nozzles and adapted for operation from a source of water under high pressure, a. manually operated main valve controlling the admission of water to the turbine, a cut-off valve individual to one of said nozzles, a differential hydraulic relay comprising a cylinder and piston therein, means for applying water at substantially the pressure of said source to one face of said piston, said one face having a substantially smaller eilective area than the other face of said piston, means for applying water to said other face ata unit pressure not in excess of the unit pressure of the water applied to said one face, and timing means responsive to the opening of said manually operated main valve for building up the total Water pressure on said other face,

whereby said piston is displaced in one direction in accordance with the diiference in total pressure to operate saidindividual valve in a closing direction, and responsive to the closing of said manually operated main valve for reducing the total water pressure on said other face, whereby said piston is displaced in the opposite direction in accordance with the difierence in total pressure to operate said individual valve in an opening direction.

EDWARD J. HAZEN.